Partway though Elvis Costello's baggy, often brilliant and wholly idiosyncratic memoir, Unfaithful Music & Disappearing Ink, there's a moment that echoes like a master metaphor. It's 1995 and our hero is about to accept "an Ivor Novello Award in the company of Van Morrison, Lonnie Donegan, and Don Black," when a BBC exec sidles up to him and says, "Of course, you'd have had a lot more hits if you'd just taken out all the seventh and the minor chords."

That this isn't the best line here is testament, I suppose, to how many good lines Unfaithful Music & Disappearing Ink contains. The implication is that Costello should have gone a more predictable route, given the programmers what they wanted — which is antithetical to the ethos of his career.

New wave rocker, country crooner, balladeer, collaborator and showman: Costello has been all of this and more in the course of what is now a 40-year run. Of all the first-generation punkers, he remains (with Patti Smith and possibly David Byrne) among the few who can claim the longevity and diversity of, say, Bob Dylan or Joni Mitchell, both of whom appear in this book. Like minds, perhaps, or water seeking its level. Either way, this is the company to which Costello belongs.

And yet, if Unfaithful Music & Disappearing Ink has anything to tell us, it is that its author remains a fan. Here he is, for instance, on his first experience singing with Paul McCartney, a rehearsal duet on "All My Loving": "I locked on to the vocal harmony the second time around, as I'd done a thousand times before while singing along to the record. It never really occurred to me that learning to sing either vocal part on a Beatles record was any kind of musical education. I was just a kid singing along with the radio in our front room." Or this, recalling a good-natured cutting contest, trading lyrics with Bob Dylan: "It was just fun to be in the ring with the champ for a minute or two."

Indeed, one of the most essential impressions with which Unfaithful Music & Disappearing Ink leaves us is that of wonder, or at least gratitude, at having been, in so many ways, in exactly the right place at the right time. "I see now that I was lucky to work in the record business during that brief interlude between the time when they bought your songs outright from you for fifty bucks or the keys to a Cadillac, and now, when everything is supposed to be free," Costello explains in the closing pages. "It's strange to recall that I wrote songs that I imagined might be sung by George Jones, Dusty Springfield, and Chet Baker and had that dream fulfilled. It is nearly impossible to explain almost anything else."

Of course, Costello is too smart to fall prey to false nostalgia; "The danger of regarding any point in the past as the golden age," he writes, "is that you forget that there were just as many crooks, crackpots and idiots around then, and just as many terrible records." For this reason, perhaps, Unfaithful Music & Disappearing Ink eschews straight chronology, moving around in time and place.

It begins with the musician's father, Ross MacManus, himself a musician, who sang with the Joe Loss Orchestra, among England's "most successful dance bands." Costello's earliest memories include watching his father perform from the balcony of the Hammersmith Palais, at the time a dance hall, later a rock venue where Costello played.

This sense of time, or music, cycling back upon itself gives the memoir its most sustaining resonance. Costello's father, after all, is a deeply influential figure, not just as role model (musical or otherwise), but also in offering a portal to another world. It was from him that his son first discovered the Beatles, in the form of acetates and demo discs brought home before their singles hit the shops. "Even though these songs were already on the radio," Costello writes, "the presence of the records in the house felt special, as if the copies had comes from The Beatles themselves."

In that regard, Unfaithful Music & Disappearing Ink is less a memoir as we've come to expect it than a kind of creative autobiography, a portrait of the artist from the inside out.

Yes, Costello touches on various points of controversy: his unfortunate remarks about James Brown and Ray Charles during a 1979 Columbus bar brawl with members of Stephen Stills' entourage; his ban from Saturday Night Live after performing "Radio, Radio" rather than "Less Than Zero," as had been planned. (His inspiration for this, it turns out, was Jimi Hendrix, who short-circuited a 1969 televised performance of "Hey Joe" in the middle, declaring "I'm going to stop playing this rubbish" before launching into Cream's "Sunshine of Your Love.")

Time overlapping again, influences emerging, which is the story of Costello's creative life. "I'm not given at all to nostalgia," he tells us, which may explain his statement that "[t]he trouble with finishing any autobiographical tome like this is that for every mildly diverting tale or precious memory, you eventually arrive at this thought: I don't much care for the subject." Still, if it's not clear to whom that "I" is referring, him or us, it's the honesty that lingers, that makes Unfaithful Music & Disappearing Ink work.

This is especially true when it comes to his composing. Costello takes us through the creation of dozens of songs, from loose lines in notebooks to final cuts. "Our musical cues should have been obvious to anyone," he admits of his early material. " 'You Belong to Me' turned the guitar lick from 'The Last Time' back to front. … 'Pump It Up' obviously took more than a little bit from 'Subterranean Homesick Blues.'"

Yes, but isn't this the nature of pop? "If I had wanted to be a poet," Costello insists, "I'd have needed to be a damn sight more accurate with my word choices, but I didn't, and still do not, necessarily see poetry as a higher, superior calling to that of the lyricist." He's absolutely right. Think of Unfaithful Music & Disappearing Ink, then, less as memoir than extended riff, not a poem but a song cycle, lyrics written in a notebook over 40 years.